Util.FSUtils:Waiting for DFS to exit Safe mode

Several times, after starting Hadoop and HBase, execute the JPS command and have seen a hmaster process,

However, entering the shell of HBase and executing a command, the following error occurs:

ERROR:org.apache.hadoop.hbase.MasterNotRunningException:Retried 7 times

Go to the logs directory to view the log of Master: Discovery always shows the following:

2013-04-13 17:13:17,374 INFO org.apache.hadoop.hbase.util.FSUtils:Waiting for DFS to exit Safe mode ... 2013-04-13 17:13:27,377 INFO org.apache.hadoop.hbase.util.FSUtils:Waiting for DFS to exit Safe mode ... 2013-04-13 17:13:37,386 INFO org.apache.hadoop.hbase.util.FSUtils:Waiting for DFS to exit Safe mode ... 2013-04-13 17:13:47,393 INFO org.apache.hadoop.hbase.util.FSUtils:Waiting for DFS to exit Safe mode ... 2013-04-13 17:13:57,395 INFO org.apache.hadoop.hbase.util.FSUtils:Waiting for DFS to exit Safe mode ... 2013-04-13 17:14:07,409 INFO org.apache.hadoop.hbase.util.FSUtils:Waiting for DFS to exit Safe mode ...

It turned out that Hadoop was still in security mode when it was first started.

[Email protected] hadoop-2.6.0-cdh5.6.0]$ Bin/hadoop dfsadmin-safemode getsafe mode is on

You can wait until Hadoop exits Safe mode and then execute the hbase command, or manually exit the security mode of Hadoop

[Email protected] hadoop-2.6.0-cdh5.6.0]$ Bin/hadoop dfsadmin-safemode leavesafe mode is OFF

Now it's no problem to execute the hbase command again.

Hadoop dfsadmin-safemode Command parameter description:

Enter    -Enter Safe mode leave    -Force Namenode to leave safe mode get      -Returns information about whether Safe mode is turned on wait     -waits until the end of safe mode.

Util.FSUtils:Waiting for DFS to exit Safe mode